1. Field of the Invention
This invention relates to the field of electronic enclosures, and in particular to enclosures suitable for ballast equipment in lighting fixtures.
2. Description of Related Art
A ballast is commonly used in lighting fixtures to provide a conversion from an available source of electricity to the voltages or currents required for effective and efficient operation of the lamps in the lighting fixture. The ballast assembly may also include the appropriate circuitry for dimming or otherwise controlling the output of the lamps.
A lighting fixture""s appearance, size, or form factor are often the key distinguishing feature among competing manufacturers. To provide the design flexibility required in order to accommodate various design styles, yet at the same time achieve the economy of scale that a commonality of components provide, manufacturers prefer components, such as ballasts, that can be used in a variety of arrangements. In the case of ballast assemblies, for example, the variety includes alternative entry points for wires, depending upon how the assembly is oriented relative to a supply cord, the lamps, a switch, and so on. Traditionally, such variety can be achieved by providing xe2x80x9cknock-outsxe2x80x9d on ballasts, wherein the manufacturer xe2x80x9cknocks-outxe2x80x9d a stamped portion of the enclosure at the desired orientation. Traditional enclosures, however, are typically made of sheet metal, and the knock-outs result in raw edges that can cause damage to the wires, or injury to the person installing the wires; escutcheons are often added to prevent such damage, further increasing the cost of the assembly. The use of knock-outs also precludes the use of conventional xe2x80x9cpush connectorsxe2x80x9d that ease manufacturing by allowing the wires to be connected to the ballast circuitry by merely pushing them into connectors that are mounted on circuit board, because the access hole in the enclosure must be aligned with the connector.
Safety issues also affect the design of ballast assemblies. Some conductors, such as those carrying the supply voltage and current, have more stringent requirements than those carrying low voltage control signals, or low lamp voltages and currents. Additionally, safety issues often mandate particular isolation requirements between different conductors.
The manufacture of ballast assemblies often include the use of xe2x80x9cpotting materialxe2x80x9d that is used to xe2x80x9cpotxe2x80x9d components onto a circuit board or other mounting surface. The potting material is applied as a semi-liquid material that is poured onto the surface before or after the component is placed onto the surface, and allowed to cure into a solid that affixes the placement of the component. The potting material may be used to provide a mechanical integrity to the mounting of a massive component, such as a transformer, or may be used to affix a particular setting of an adjustable component, such as a trimming resistor, or it may be applied to provide a thermal coupling between components that generate heat and corresponding components that regulate the heat. The use of potting material is often problematic with regard to the use of the push-connectors discussed above. A small amount of potting material can render the spring mechanisms of push-connectors inoperative or unreliable. An unreliable connection is often not detected until late in the manufacturing process, or until the light fixture is installed at a consumer""s location. The resultant repair cost, and potential damage to the manufacturers reputation, caused by a late discovery of a problem can be substantial.
It is an object of this invention to provide a ballast assembly that can support a variety of installation configurations. It is a further object of this invention to provide a ballast assembly that can be alternatively configured without using knock-outs. It is a further object of this invention to provide a ballast assembly that facilitates ease of manufacture. It is a further object of this invention to provide a ballast assembly that facilitates adherance to safety issues and mandates. It is a further object of this invention to provide a ballast assembly that protects connectors from materials that are used in the assembly during the manufacturing process.
These and other objects are achieved by providing a ballast assembly that facilitates alternative wiring configurations through the use of one or more dual-port connectors with corresponding insulating covers. The dual-port connectors provide a choice of wiring options, and the insulating cover provides the protection of the connector from the ingress of materials during the manufacturing process. In a preferred embodiment, the insulating cover is configured to reduce the potential of damage, to people or equipment, during the assembly of a lighting fixture containing this ballast assembly, and is also configured to provide the electrical isolation and protection required or desired for safety concerns. In a preferred embodiment, the insulating connector forms access regions about each port of the dual connector that are physically and electrically isolated from one another, and physically and electrically isolated from the access holes in the enclosure material, which is typically sheet metal.